1. Field of the Invention
The present invention relates to a magnetic head and a manufacturing method thereof, and more particularly, to a magnetic head in which adhesion of a diamond-like carbon layer is improved and a manufacturing method therefor.
2. Description of the Related Art
Devices such as a videocassette recorder, an audio cassette tape player and a disk drive of a computer adopt a magnetic head as a means for performing magnetic recording and reading out of information. The magnetic head consists primarily of a magnetic metal material, i.e., ferrite. In the videocassette recorder, for example, a magnetic layer of video tape is formed by evenly depositing fine ferromagnetic powder on a base of polyester using a resin binder. The magnetic head made of ferrite contacts the magnetic layer of the video tape, i.e. the recording medium, thereby reading out information recorded thereon in a known manner.
As described above, the magnetic head continuously contacts the recording medium having the magnetic layer, so that the surface of the magnetic head may be abraded. In order to prevent abrasion of the magnetic head, a diamond-like carbon (DLC) layer with a high degree of hardness typically is deposited on the surface of the magnetic head.
FIG. 1 is a flowchart illustrating a method for manufacturing a magnetic head for the videocassette recorder, suggested by the present inventor. FIG. 2 illustrates the chip core manufacturing step 11 of FIG. 1 in detail, and FIG. 3 is a perspective view of the magnetic head manufactured according to the method of FIG. 1.
Referring first to FIG. 2, in manufacturing the chip core of the magnetic head from blocks of ferrite stock 21a and 21b, winding slots and track channels are formed in the opposing surface thereof, which then undergo polishing to thereby form chip core halves 21a' and 21b'. Silicon oxide (i.e., a non-magnetic substance) layers 22a and 22b are deposited on the respective polished surfaces and the thus-processed ferrite blocks 21a" and 21b" are combined. A chip core block 24 is formed through a predetermined process of shaping and polishing and then is sliced into chip cores 25. The obtained chip core includes an upper surface 26 and a gap 27.
Referring now to FIG. 1, after manufacturing the chip core in step 11 as described above, the chip core is assembled with a substrate in step 12. Here, the chip core 25 is attached to a head base (not shown) through ultraviolet bonding. Then, after a coil is wound around the chip core 25 in step 13, the dynamic characteristics of the primarily completed magnetic head are evaluated in step 14 to screen out inferior products and thus prevent unnecessary subsequent processing for heads which would ultimately fail final analysis. In step 15, the pre-screened chip cores with windings, and especially the upper surfaces thereof, are washed by air bubbles generated by an ultrasonic wave generator installed in a bath, and then dried by a hot-air drying method. In step 16, the upper surface 26 is first smoothed by etching with ionized argon gas (Ar.sup.+) and a DLC layer is formed thereon through two deposition processes to provide a uniform coating. The deposition is performed by known methods such as chemical vapor deposition (CVD) or physical vapor deposition (PVD). Another dynamic characteristic examination is performed in step 17 for examining the characteristics of the final magnetic head. Thereafter, the magnetic heads are paired together for installation in a head drum, by selection according to the dynamic characteristics obtained in step 17.
FIG. 3 shows a magnetic head manufactured by the steps noted above. In FIG. 3, the magnetic head comprises a chip core 25 including two core members 25a and 25b separated by the gap 27 having a width W, coils 28 wound around the core members, and a DLC layer 29 deposited on the upper surface 26 of the chip core 25. Also, a recess 30 which communicates with and end of the gap 27 is formed in the upper surface 26 and is filled with reinforced glass (not shown) to define a gap length L.
The DLC layer of the magnetic head manufactured by the method above is as a solid amorphous film and has the same hardness, lubricant properties, anti-abrasion properties, electrical insulating properties and chemical stability as a diamond. However, even though the hardness of the DLC layer is efficient for preventing abrasion of the magnetic head, the DLC layer may be easily separated from the ferrite due to a force generated when the magnetic head contacts the video tape. Also, ferrite particles which become separated from the ferrite core, act as a foreign substance between the magnetic head and the recording medium.